1. Technical Field
The present invention relates to an image display device, an image display system, and a network connection method.
2. Related Art
In recent years, it has become possible that when performing a presentation or a report in a conference, materials stored in a personal computer (hereinafter referred to as a “PC”) or the like as digital data are enlargedly displayed by a projector, thereby making a number of participants view the contents of the presentation. Further, in recent days, it has become possible to perform the data transfer from a PC to a projector wirelessly by using a projector capable of performing wireless communication with a wireless local area network (LAN). By using such a projector, the cable can be prevented from becoming an obstacle, and further, even in the case in which a number of presenters perform presentations while taking turns using respective PCs, operations for reconnecting the cable can be eliminated.
However, in order for establishing network connection from the PC to the projector with the wireless LAN, necessary connection information including, for example, an IP address of the projector, an identifier such as an extended service set identifier (ESSID) identifying a network name or a password in the wired equivalent privacy (WEP) which is an encryption technology for communication data needs to be input in the PC. In order for performing the input operation, it is required to previously investigate the connection information of the projector, and further, even if the connection information has been figured out, it is still difficult to perform the input operation without knowledge about the network.
In consideration of such a problem, the brochure of International Patent Publication No. WO2003/015451 discloses a technology for simply and easily accessing from one electronic equipment (e.g., a portable information terminal) to other electronic equipment (e.g., a projector). In the image display system described in the document, the connection information (ID information) for connecting to the projector is attached to the projector itself or a part of the screen in a form of a contact-free tag or a barcode, and the portable information terminal is arranged to be able to establish the network connection with the projector based on the connection information when the user moves the portable information terminal equipped with a contact-free tag reader or a barcode reader close to the projector or the screen to make the portable information terminal read the connection information.
However, in the image display system described in the document, the operation for attaching the contact-free tag or a barcode material (a printed material) to the projector or the screen as the ID information is required, and further, there is a concern that a wrong ID information might be attached in the operation. Further, since it is required to move the portable information terminal close to the projector or the screen in reading the attached ID information, the user must move bringing the portable information terminal every time the connection is performed.